Simplify the following expression: ${3(3n+12)+2(-1-2n)}$
Solution: Distribute the ${3}$ into the first set of parentheses: $ {3(}\gray{3n+12}{)} + 2(-1-2n) $ $ {9n+36} + 2(-1-2n) $ Distribute the ${2}$ into the parentheses: $ 9n+36 + {2(}\gray{-1-2n}{)} $ $ 9n+36 {-2-4n} $ Rewrite the expression to group the ${n}$ terms and numeric terms: $ {9n - 4n} + {36 - 2}$ Combine the ${n}$ terms: $ {5n} + {36 - 2}$ Combine the numeric terms: $ {5n} + {34}$ The simplified expression is $5n+34$